The present invention relates to a screening examination technology and more particularly, to a screening examination system which performs inspection and screening during conveying of test products. The invention relates also to a screening examination method using the screening examination system.
FIG. 1 illustrates a screening system according to the prior art. According to this design, the screening system 10 comprises a first conveyor unit 11, a second conveyor unit 13 arranged at the same elevation relative to the first conveyor unit 11 and kept apart from the first conveyor unit 11 at a gap 12, and a top conveyor unit 14 arranged above the first conveyor unit 11 and a second conveyor unit 13. The first conveyor unit 11 comprises a first drive wheel 111, a first driven wheel 113 and a first conveyor belt 15 wound around the first drive wheel 111 and the first driven wheel 113. The second conveyor unit 12 comprises a second drive wheel 131, a second driven wheel 133 and a second conveyor belt 17 wound around the second drive wheel 131 and the second driven wheel 133.
During application, the top conveyor unit 14, the first conveyor unit 11 and the second conveyor unit 13 are rotated to deliver test products 19. The first drive wheel 111 and the second drive wheel 131 are drive sources controlled to move the first conveyor belt 15 and the second conveyor belt 17, thereby delivering the test products 19. In actual practice, the transverse width L of the gap 12 is approximately equal to the width L1 of the test products 191. Thus the test products 191 that are carried forwards by the first conveyor belt 15 will be delivered to the second conveyor belt 17 subject to an inertia effect. Any test product 19 of which the transverse width L2 is smaller than the transverse width L of the gap 12 is regarded as a defective product 193. When one defective product 193 is being delivered by the first conveyor belt 15 toward the second conveyer belt 17, the defective product 193 will fall into the gap 12.
Further, there are limitations on the use of the aforesaid prior art screening system 10. For example, when the transverse width L2 of one defective product 193 is slightly smaller than the transverse width L of the gap 12, the defective product 193 may be delivered from the first conveyor unit 11 over the gap 12 to the second conveyor unit 13 due to the effect of inertia, subsequently, when one defective product 193 falls down as it is being delivered by the first conveyor belt 15 toward the second conveyer belt 17, the defective product 193 may be carried over the gap 12 to the second conveyer belt 17 regarding the effect of inertia as well, lowering the screening accuracy.
Therefore, it is desirable to provide a screening examination system and method that eliminates the aforesaid problem.